1. Field of the Invention
The invention group relates to methods of the thermochemically augmenting hydrocarbon inflow from a production formation while producing oil, gas and gas condensate in the oil industry.
2. Background of the Invention
Russian Patent No. RU 2064576 describes a well-known method of thermochemical treatment of production formation that includes pumping combustible-oxidizing compound (COC) into the formation treatment zone, where the COC contains ammonium nitrate, water, sal ammonia and/or dibasic ammonium phosphate, and introducing a combustion initiator into the COC zone, with the combustion initiator being a powder explosive charge. The prolonged treatment time, usage of the explosive and the rather complicated realization of the method restrict its applicability.
Another method described in Russian Patent No. RU 2126084 involves thermochemical treatment of the production formation that includes pumping-down the COC into the formation treatment zone and delivering the combustion initiator comprising a blend of metal aluminum and green rough into the treatment zone.
To implement this method, a COC is used that contains a complex compound of an amide such as carbamide and nitric acid, a compound with an acetate group such as acetic acid, potassium permanganate, fluid isopropylcarborane, water and ammonium nitrate.
The present invention proposes to provide a method of thermochemically treating a producing formation that increases treatment efficiency due to a fast forming of a large amount of hydrogen of high penetrability and to the increased energy-conversion efficiency of the process.
The invention comprises a thermochemical treatment of the producing formation, which includes pumping the combustible-oxidizing compound (COC) into the formation treatment zone and introducing the combustion initiator into the treatment zone. The combustion initiator comprises a solid or liquid composition on the base of a metal and/or metalloid hydride.
The liquid composition of the combustion initiator on the base of a metalloid hydride may be a suspension solution of a borane on the base of an organic dissolvent such as diethyl ether or methyl alcohol, at the following blending ratio, percent of total mass:
If the combustion initiator is on the base of metalloid hydride and has a solid composition, it may be a blend of a borane with alkali and/or solid isopropylcarborane at the following blending ratio, per cent of total mass:
The combustion initiator can be introduced by descending a hermetic container containing the combustion initiator into the tubing pipe string via an industrial hoist and then demolishing the container by detonating a backoff shot mounted along the entire container length after the terminations of the cord hoist contact the power source at the shoe of the tubing pipe string.
The fluid composition of the combustion initiator could be delivered to the treatment zone by pumping-down, in the following method:
First, the bottom of the tubing pipe string is sunk into the formation treatment zone;
Next, the consecutive pumping-down of the following chemicals occurs: combustion-oxidizing compound, dehydrated hydrocarbonaceous fluid, combustion initiator and extrusion liquid;
Then, the COC is pumped into the treatment zone by extrusion from the specified string and lifting the pipe string up to the top level of the COC;
The dehydrated hydrocarbonaceous fluid is pumped out;
The pipe string is sunk up to the middle of the work formation zone; and
The combustion initiator is pumped out of the specified pipe string directly to the COC.
If the bedding depth of the formation is less than 1200 m, the treatment zone is isolated by setting up packers at a distance of 45-55 m over the perforation zone of the casting tube.
The COC preferably contains a complex compound of an amide and nitric acid, a compound with an acetate group, potassium permanganate, isopropylcarborane, water and ammonium nitrate. The COC preferably contains an oxalic acid diamide as the amide and acetic ether of salicylic acid as the compound with acetate group, at the following blending ratio, percent of total mass:
The COC can also contain calcium salicylate (0.05-1.5 percent of total mass) as a reaction retarder, and potassium chloride (0.001-0.005 percent of total mass), saccharose or glucose (0.05-3 percent of total mass) as a combustion stabilizer.
The metal hydrides in the combustion initiator contact water in the coc composition and immediately release a large amount of hydrogen of high penetrability, which penetrates at high speed into pores and cracks of the well, cleanses them by cracking and pyrolysis of asphaltic-gumming paraffin-hydrate compounds, and contributes to increasing old cracks and creating new ones. The posterior penetration of oxidizing gas into these pores results in the combustion process there. Therefore, the majority of the energy release occurs in pores and cracks of the formation, not in the very borehole, which greatly increases the efficiency of the thermochemical treatment.
Using the complex compound of oxalic acid diamide and nitric acid in the COC composition increases the energy-conversion efficiency of the COC due to the substitution of ammonium carbamide, (urea) for ammonium oxamide (oxalic acid diamide), and increases labor safety, as long as the ammonium carbamide binds the nitric acid to the more durable compound in the preparatory process.
Using an acetic ether of salicylic acid instead of acetic acid more effectively eliminates the detonation processes in the combustion.
The addition of solid isopropylcarborane to the COC composition homogenizes the combustion initiator composition and provides for an even energy emission directly in the work producing formation, and essentially augments the energetic potential of the initiating compound, including the energy share being consumed for hydrocarbon cracking.